Route planning devices are well known in the field of navigational instruments. The capabilities of known route planning devices and methods depend on system resources, such as processor speed and the amount and speed of memory. The processes implemented by a navigational aid device are a function of overall system cost because an increase in system capability also increases system cost. The known art includes a spectrum of products in which the degree of accuracy and the amount and quality of information is dictated primarily by the cost of the system. The lower cost systems currently offer a lower degree of accuracy that often is inadequate for most users, and offer an amount and quality of information that is less than desired for most users.
Processes inherently affected by the limited system resources include route planning, route guidance and other guidance or information provided to assist a user of the device. Route planning involves calculating a route between a starting position and an ending destination. Route guidance guides a user through the appropriate maneuvers to navigate through a planned route. The system requirements for both route planning and route guidance are considerable as these processes involve algorithms or operating instructions acting on a large amount of cartographic data. As such, given the limited system resources and the requirements of route planning and route guidance, other guidance or assistance for the user of the navigational aid device often is not provided with the device.
Route planning and route guidance are useful features in a navigational device. However, other guidance or information is often desirable for a number of reasons. For example, a user may be a local person who knows how to travel to the general location of the ending destination. As such, the user neither needs nor desires to plan a route to the general location of the ending destination. Another example involves a user who has been guided along a planned route, and now is located in the general destination.
Often, these users are traveling to a particular business or residential address for the purpose of an appointment, a delivery, or a social event, for example. The users are somewhat familiar with the area, but are unsure of the location of the building for the desired building or residential address.
These addresses are not easily identified from the road for a number of reasons. For example, the address signs may be inconsistently placed on buildings. Additionally, address signs often are inconsistent in size, and contain inconsistent lettering size and type. Furthermore, the address signs may not be illuminated in the dark. Other reasons involve the distance from the road to the address signs, and the traffic flow speed such that sufficient time for finding address signs is not available. As there may be other reasons why addresses are not easily identified from the road, these examples are not intended as an exhaustive list.
Therefore, there exists a need for a navigational aid device that provides an address that is proximate to the device, and that updates the address as the navigational aid device is transported.